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Measurement of the Ratio R=BR(B<sup>-</sup></b></font><font
 color="#0000aa" size="+4"><b>-&gt;D<sup>0</sup>K<sup>-</sup>)/BR(B<sup>-</sup></b></font><font color="#0000aa" size="+4"><b>-&gt;D<sup>0</sup>&#960;<sup>-</sup>) in 360 pb<sup>-1</sup>.<br>
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<p>This webpage summarizes the results for the measurement
of R = BR(B<sup>-</sup>-&gt;D<sup>0</sup>K<sup>-</sup>)/BR(B<sup>-</sup>-&gt;D<sup>0</sup>&#960;<sup>-</sup>).<br/>
This preliminary result was approved on April 20, 2006.</p>
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<h1>Abstract </h1>
<p>The partial widths of B<sup>-</sup>-&gt;D<sup>0</sup><sub>(CP)</sub>K<sup>-</sup> decays (D<sup>0</sup>-&gt;K<sup>-</sup>&#960;<sup>+</sup> and D<sup>0</sup><sub>CP+</sub>-&gt;K<sup>+</sup>K<sup>-</sup>, &#960;<sup>+</sup>&#960;<sup>-</sup>) provide a theoretically clean way of measuring the CKM angle gamma.  <br>
We present the measurement of the ratio R = BR(B<sup>-</sup>-&gt;D<sup>0</sup>K<sup>-</sup>)/BR(B<sup>-</sup>-&gt;D<sup>0</sup>&#960;<sup>-</sup>) that is the first step through the gamma angle measurement. <br>
The value of the ratio is:<br>
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R = 0.065 &plusmn 0.007 (stat) &plusmn 0.004 (sys)
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<h1>Description </h1>
<p>A complete description of the analysis is available here: <a
 href="public_note/BDK_public.ps">note-8242</a>.
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    <img align=middle src="mass_proj.gif">
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<h1>Figures </h1>
<p>Below the .eps and .gif versions of all figures available for download.
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<ul>
  <li> Generic MC of B<sup>-</sup>-&gt;D<sup>0</sup>&#960;<sup>-</sup> </li>
  <ul>
    <li> <a href="MC_bless.eps"> generic MC </a>&nbsp;&nbsp;&nbsp;
      <a href="MC_bless.gif"> (gif) </a></li>
    <li> <a href="MC_zoom_bless.eps"> generic MC zoom </a>&nbsp;&nbsp;&nbsp;
      <a href="MC_bless_zoom.gif"> (gif) </a></li>
 <p></p>
  </ul>
 <li> Data sample </li>
  <ul>
    <li> <a href="massa_cut_bless.eps"> Invariant mass distribution </a>&nbsp;&nbsp;&nbsp;
      <a href="massa_cut_bless.gif"> (gif) </a></li>
   <p></p>
  </ul>
 <li> Mass vs &#945 </li>
  <ul>
    <li> <a href="massa_vs_alfa_bless.eps"> Mass vs &#945 </a>&nbsp;&nbsp;&nbsp;
   <a href="massa_vs_alfa_bless.gif"> (gif) </a></li>
   <p></p>
  </ul>
  <li> p<sub>tot</sub> distributions for B<sup>-</sup>-&gt;D<sup>0</sup>&#960;<sup>-</sup> and B<sup>-</sup>-&gt;D<sup>0</sup>K<sup>-</sup></li>
  <ul>
    <li> <a href="ptot_Dpi_bless.eps"> ptot_BD0pi </a>&nbsp;&nbsp;&nbsp;
      <a href="ptot_dpi.gif"> (gif) </a></li>
    <li> <a href="ptot_dk_bless.eps"> ptot_BD0K </a>&nbsp;&nbsp;&nbsp;
      <a href="ptot_dk.gif"> (gif) </a></li>
  <p></p>
  </ul>
  <li> p<sub>tot</sub> distribution for the physics background: B<sup>-</sup>-&gt;D<sup>*0</sup>&#960;<sup>-</sup></li>
  <ul>
    <li> <a href="ptot_dstrpi_bless.eps"> ptot_BDstrpi </a>&nbsp;&nbsp;&nbsp;
      <a href="ptot_dstrpi.gif"> (gif) </a></li>
   <p></p>
  </ul>
  <li> p<sub>tot</sub> distribution for the combinatorial background </li>
  <ul>
    <li> <a href="ptot_comb_bless.eps"> ptot_back </a>&nbsp;&nbsp;&nbsp;
      <a href="ptot_comb.gif"> (gif) </a></li>
 <p></p>
  </ul>
  <li> (&#945;,p<sub>tot</sub>) joint distributions for B<sup>-</sup>-&gt;D<sup>0</sup>&#960;<sup>-</sup> and B<sup>-</sup>-&gt;D<sup>0</sup>K<sup>-</sup> </li>
  <ul>
    <li> <a href="2D_dis_dpi_bless.eps"> alpha_ptot_BD0pi </a>&nbsp;&nbsp;&nbsp;
      <a href="dis_2D_dpi.gif"> (gif) </a></li> 
      <a href="fit_2D_dpi.eps"> alpha_ptot_BD0pi_fit </a>&nbsp;&nbsp;&nbsp;
      <a href="fit_2D_dpi.gif"> (gif) </a></li><br>
    <li> <a href="2D_dis_dk_bless.eps"> alpha_ptot_BD0K </a>&nbsp;&nbsp;&nbsp;
	 <a href="dis_2D_dk.gif"> (gif) </a></li> 
      <a href="fit_2D_dk.eps"> alpha_ptot_BD0K_fit </a>&nbsp;&nbsp;&nbsp;
      <a href="fit_2D_dk.gif"> (gif) </a></li><br>
      <p></p>
  </ul>
  <li> (&#945;,p<sub>tot</sub>) joint distributions for the physics background B<sup>-</sup>-&gt;D<sup>*0</sup>&#960;<sup>-</sup>
  <ul>
    <li> <a href="2D_dis_dstrpi_bless.eps"> alpha_ptot_BDstrpi </a>&nbsp;&nbsp;&nbsp;
      <a href="dis_2D_dstrpi.gif"> (gif) </a></li> 
      <a href="fit_2D_dstrpi.eps"> alpha_ptot_BDstrpi_fit </a>&nbsp;&nbsp;&nbsp;
      <a href="fit_2D_dstrpi.gif"> (gif) </a></li><br>
      <p></p>
  </ul>
  <li> (&#945;,p<sub>tot</sub>) joint distribution for the combinatorial background background</li>
  <ul>
    <li> <a href="2D_dis_comb_bless.eps"> alpha_ptot_bkg </a>&nbsp;&nbsp;&nbsp;
      <a href="dis_2D_comb.gif"> (gif) </a></li>
      <a href="fit_2D_comb.eps"> alpha_ptot_bkg_fit </a>&nbsp;&nbsp;&nbsp;
      <a href="fit_2D_comb.gif"> (gif) </a></li><br>
    </ul>
  <li> Fit Projections
  <ul>
    <li> <a href="mass_bless.eps"> Invariant D<sup>0</sup>&#960;-mass</a>&nbsp;&nbsp;&nbsp;
      <a href="mass_proj.gif"> (gif) </a></li> 
      <a href="alpha_bless.eps"> alpha </a>&nbsp;&nbsp;&nbsp;
      <a href="alpha_proj.gif"> (gif) </a></li><br>
      <a href="ptot_bless.eps"> ptot </a>&nbsp;&nbsp;&nbsp;
      <a href="ptot_proj.gif"> (gif) </a></li><br> 
      <a href="ID_bless.eps"> ID </a>&nbsp;&nbsp;&nbsp;
      <a href="ID_proj.gif"> (gif) </a></li><br>
      <p></p>
  </ul>
  <li> PR-PLOT of DCP decays
  <ul>
    <li> <a href="KK_bless_fit.eps"> Invariant D<sub>CP</sub>&#960;-mass with D<sub>CP</sub>-&gt;K K;</a>&nbsp;&nbsp;&nbsp;
      <a href="KK.gif"> (gif) </a></li> 
      <p></p>
  </ul>
  <ul>
    <li> <a href="pipi_bless_fit.eps"> Invariant D<sub>CP</sub>&#960;-mass with D<sub>CP</sub>-&gt;&#960; &#960;</a>&nbsp;&nbsp;&nbsp;
      <a href="pipi.gif"> (gif) </a></li> 
      <p></p>
  </ul>
</ul>
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